Bleaching with organic bleaching agent



Patented Mar. 28, 1939 BLEACHING WITH ORGANIC BLEACHING AGENT Paul J. Carlisle, Niagara Falls, N. Y., asslgnor to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application December 30, 1937, Serial No. 182,625

3 Claims.

This invention relates to a novel and superior bleaching agent. More specifically, it relates to the use of the stable organic hypochlorite, tertiary .butyl hypochlorite, having the formula (CH3):C. OC1 as a bleaching agent for bleaching material such as cotton, wool, and other textile fibers and fabrics generally, foodstufis such as fruit and butter, and fatty and waxy materials such as wool fat, various oils and sulphonated oils, and various waxes.

The alkyl hypochlorites including tertiary butyl hypochlorite have already been prepared. As the lower members of the series were found to be relatively explosive, and all of these hypochlorites generally unstable, no attempt at commercial utilization of the compounds has been made. Recent research has nowfindicated that the tertiary alkyl hypochlorites are more stable than the primary and secondary hypochlorites. Among the tertiary alkyl hypochlorites, I have found that tertiary butyl hypochlorite, (CH3)-3C.OC1, is remarkably efiicacious as a bleaching agent for almost any bleaching pur pose where hYDOChIOlOllS acids, hypochlorites, or peroxygen compounds are at present employed.

Tertiary butyl hypochloriate is a pale yellow liquid which is exceedingly stable if kept out of bright light. It is relatively insoluble in water and soluble in various organic solvents such as the chlorinated hydrocarbon solvents, e. g. trichlorethylene, methylene chloride, carbon tetrachloride, perchlorethylene etc., the hydrocarbon solvents such as naphtha, and other petroleum fractions, and in alcohols such as methanol and ethanol. It boils at about 80 C. at atmospheric pressure. While it will quitely decompose when stored for some time in the bright sunlight, it is stable in diffused light and exceedingly stable when kept in the dark.

In view of the insolubility of tertiary butyl hypochlorite in water, it has been found most advantageous to dissolve the bleaching agent in an organic solvent and apply it to the material to be bleached dissolved in that solvent. Thus, in the bleaching of cotton or other textile fibers or fabrics it may be dissolved in a chlorinated hydrocarbon solvent such as trichlorethylene, carbon tetrachloride, perchlorethylene or methylene chloride and applied in that solvent to the fabric to be bleached. Similarly, it may be dissolved in any of the hydrocarbons such as benzene or petroleum fractions, or in an alcohol.

When utilizing tertiary butyl hypochlorite for the bleaching or deodorizing of butter, it is merely necessary to introduce a small amount of thisbleaching agent into the butter, thoroughly emulsifying it therein. Similarly, for the bleaching of fats or waxes the tertiary butyl hypochlorite may ordinarily be thoroughly interspersed throughout the solid material to be bleached and 5 need not be applied thereto by means of a solvent. Since some dark-colored materials which are normally bleached commercially will dissolve tertiary butyl hypochlorite it is only necessary in bleaching these materials to introduce a small amount of organic hypochlorite and secure thorough solution therein by agitation.

As an example of the preparation and use of my novel and improved bleaching agent, the following may be given:

Example A quantity of tertiary butyl hypochlorite was prepared by adding one mole of tertiary butyl alcohol to a strong solution of caustic soda containing 2 moles of NaOH. Sufilcient water was added to form a homogeneous mass. Chlorine gas was then passed through the solution, ice water being applied to the reaction vessel in order that the reaction mixture might be maintained at a relatively low temperature.

A yellow mobile layer which was insoluble in the solution separated. This constituted tertiary butyl hypochlorite and it was secured in substantially quantitative yields. The yellow liquid was then removed from the aqueous residue and dried by rapid passage over fused calcium chloride. It was of pale yellow colorand possessed a characteristic odor. Its vapor had an irritating effect upon the eyes and mucous membrane -of the nose,

Solutions of 2.5% concentration of this compound in each of the following organic solvents were prepared: trichlorethylene, methylene chloride, carbon tetrachloride, naphtha, and ethanol. These solutions were applied to darkcolored cotton materials. Even at roomtemperature substantial bleaching was apparent,

' which was increased by elevation of the temperamaterial being bleached or deodorized and the 2 nature and extent of dark-colored substances present. Various changes may be made in the mode of application of my improved bleaching agent, which may also be used for bleaching materials other than those specified above as illustrative. The invention is not to be restricted to precise numerical amounts, to treatment of specifled fabrics or foodstuffs, or to the utilization of the tertiary butyl hypochlorite as bleaching agent only when dissolved in a solvent therefor, but is to be construed in accordance with the appended claims.

I claim:

1. A process of bleaching dark-colored materials which comprises contacting said materials with tertiary butyl hypochlorite.

2. A process of bleaching textile fabrics which comprises contacting said fabrics with tertiary butyl hypochlorite. I

3. A process of bleaching textile fabrics which comprises contacting said fabrics with a solution comprising tertiary butyl hypochlorite dissolved 10 in an organic solvent.

PAUL J. CARLISLE. 

